The present invention relates to an information recording/reproducing device having plural disk drive units each including a reproduction control program and a CPU (Central Processing Unit) for executing it, and, for example, to techniques applied adaptively to bug corrections or upgrades of reproduction control programs in an information recording/reproducing device capable of reproduction of audio CD (Compact Disk) and dubbing to audio CD-RW (Compact Disk-rewritable) or audio CD-R (Compact Disk-recordable), or an information recording/reproducing device including plural DVD (Digital Video Disk) drive units capable of dubbing.
Audio disk (CD, etc.) drives or video disk (DVD, etc.) drives have optical and mechanical components and a control circuit that controls them and performs data processing such as signal processing including filtering. The control circuit comprises a microcomputer and an operation program thereof. The operation program, if a bug is found, must be corrected, and must be upgraded to extend functions. To satisfy such demands, a technique is provided for enabling bug corrections and upgrades without using a host device such as a personal computer. According to this technique, a dedicated disk in which new control programs are recorded is mounted in a disk drive to thereby rewrite program memories such as flash memories incorporated in a microcomputer. This technique is described in Japanese Published Unexamined Patent Application Nos. Hei 7-262690, 11-45496, and 7-248914.
Recently, a law for making it possible to levy music royalties on the media side has been enacted, with the result that it has become possible to provide an information recording/reproducing device capable of reproduction of audio CD and dubbing to audio CD-RW or audio CD-R. The inventor studied the handling of bug corrections and upgrades of reproduction control programs for plural disk drives in audio equipment and video equipment. The study showed that, if a host device such as a personal computer is not used, the prior art dictates remounting an information recording medium in which new control programs are recorded in respective drives to individually perform program rewriting. This would worsen operability such as updating of an access control program and other programs and function extensions by end users immediately before shipment of an information recording/reproducing device. Individually providing a medium in which new control programs are recorded for each of disk drives would be troublesome to information recording/reproducing device manufacturers. The same is also true for optical disk mounting equipment such as car audio systems in which navigation and audio are integrated.
An object of the present invention is to provide an information recording/reproducing device that permits a reproduction control program or the like in each of plural disk drive units to be subjected to bug corrections and upgraded without using a host device, even if an information recording medium in which new control programs are recorded is not remounted in the respective drives to individually perform program rewriting.
Another object of the present invention is to provide a computer-readable recording medium in which new control programs are recorded and which need not be provided for each of plural disk drive units, when a reproduction control program or the like in each of the disk drive units is subjected to bug corrections and upgraded without using a host device.
The above described objects and other objects, and novel characteristics of the present invention will become apparent from this specification and the accompanying drawings.
Typical ones of inventions disclosed by this application will be described briefly.
[1] In an information recording/reproducing device according to the present invention, programs stored in electrically programmable nonvolatile memories are executed by CPUs, plural disk drive units adapted to enable access to an information recording medium are provided, and the plural disk drive units are connected over an interface bus. To provide for bug corrections and upgrades for the programs stored in the flash memories, one disk drive unit uses predetermined recording information of a mounted information recording medium to rewrite a program stored in a nonvolatile memory of the one disk drive unit, and transfers a program to another disk drive unit to instruct program rewriting. According to the rewriting instruction from the one disk drive unit, the other disk drive unit rewrites a program stored in a nonvolatile memory thereof.
From the foregoing, if the information recording medium is reproduced in one disk drive unit, since program information can be transferred to a different disk drive unit, without having to remount an information recording medium in which new control programs are recorded in the respective disk drive units to individually perform program rewriting, a reproduction control program or the like in each of the plural disk drive units can be subjected to bug corrections and upgraded without using a host device. Therefore, updating of an access control program and other programs and function extensions by end users immediately before shipment of a product can be achieved with simple operations.
When program rewriting is performed in the one and other disk drive units, preferably the one disk drive unit performs program rewriting after program rewriting has been performed in the other disk drive unit. Since access control for the information recording medium may be disabled due to power failure, data errors, or other faults occurring in the course of program rewriting, if program rewriting is performed last in the one disk drive unit that accesses the information recording medium in which new control programs are recorded, access to the information recording medium can be retried however often failures occurred previously, providing safety and reliability for the program rewriting operation.
[2] As a more detailed method of program rewriting for the nonvolatile memories, in terms of program rewriting efficiency, preferably, the one disk drive unit temporarily holds a rewriting program read from an information recording medium in a buffer RAM before writing it to a nonvolatile memory, while the other disk drive unit temporarily holds a rewriting program supplied from the one disk drive unit before writing it to a nonvolatile memory.
The one disk drive unit has the storage area of an interface control program and the storage area of a rewriting control program wherein the interface control program stores a program for the one disk drive unit stored in the mounted information recording medium in one buffer RAM of the one disk drive unit, and transfers a program for another disk drive unit stored in the mounted information recording medium to the other disk drive unit to instruct writing to the other buffer RAM, while the rewriting control program rewrites a program held in a nonvolatile memory of the one disk drive unit to the program held in the one buffer RAM. The other disk drive unit has the storage area of an interface control program and the storage area of a rewriting control program wherein the interface control program, in response to the instruction to write to the other buffer RAM given from the one disk drive unit, stores the program from the one disk drive unit in the other buffer RAM, while the rewriting control program rewrites a program held in a nonvolatile memory of the other disk drive unit to the program held in the other buffer RAM.
The respective nonvolatile memories of the disk drive units may have the storage area of the rewriting control program, and the storage area of the interface control program, in addition to the storage area of an access control program for accessing an information recording medium. The rewriting control program and the interface control program also become rewritable.
In this case, it is desirable that the storage areas of the rewriting control program and the interface control program in the nonvolatile memories can be rewritten mutually independently of the storage areas of the access control program and other programs. Even if a failure occurs in the course of rewriting the access control program and other programs, since the rewriting control program and the interface control program remain intact, the access control program and other programs can be again written to the flash memories from the buffer RAMs, providing safety, reliability, or efficiency for the program rewriting operation.
[3] As a further concrete embodiment of the information recording/reproducing device, for example, assuming that it is capable of reproduction of audio CD and dubbing to audio CD-RW or audio CD-R, it may further have an audio circuit that inputs digital audio data read from an information recording medium mounted in the respective disk drive units and can reproduce it to a sound signal, wherein at least one of the disk drive units inputs digital audio data read from an information recording medium mounted in another disk drive unit over the interface bus and can write it to an information recording medium mounted in the one disk drive unit.
Assuming that an information recording/reproducing device includes plural DVDs (Digital Video Disks) so as to be capable of dubbing, it may further have a reproducing circuit that inputs and can reproduce digital data read from an information recording medium mounted in the respective disk drive units, wherein at least one of the disk drive units may input digital data read from an information recording medium mounted in another disk drive unit over the interface bus to write it to an information recording medium mounted in the one disk drive unit.
The CPU and the nonvolatile memory may be constituted by a microcomputer formed on one semiconductor chip.
[4] A computer-readable recording medium according to the present invention is a recording medium such as CD-ROM in which a first access control program executed by a first CPU for instructing a first disk drive unit to access an information recording medium, a second access control program executed by a second CPU for instructing a second disk drive unit to access an information recording medium, and information for identifying the first access control program and the second access control program are recorded in a computer-readable form.
When a reproduction control program or the like in each of the plural disk drive units is subjected to bug corrections and upgraded without using a host device, a computer-readable recording medium in which a new control program is recorded need not be provided for each of the disk drive units. The disk drive units determine which access control program should be rewritten in which disk drive, based on the identification information.
Assuming that the information recording/reproducing device is capable of reproduction of audio CD and dubbing to audio CD-RW, the recording medium is a computer-readable CD-ROM medium in which a first access control program for instructing a CD-ROM disk drive unit having a CPU to access CD-ROM media, a second access control program for instructing a CD-RW disk drive unit having a CPU to access CD-RW media, and the file identification information of the first access control program and the second access control program are recorded so as to be accessible in the CD-ROM disk drive unit or CD-RW disk drive unit.